B GB 7 0 7 L 7 E SD B GB 7 0 7 L 7 E SD a s a B ro a d b a n d L o w No i s e A m p l i fe r fo r mo b i l e a n a l o g TV a p p l i c a ti o n s Ap p l i c a ti o n N o te A N 2 3 2 Revision: Rev. 1.0 2010-08-03 RF a n d P r o te c ti o n D e vi c e s Edition 2010-08-03 Published by Infineon Technologies AG 81726 Munich, Germany © 2010 Infineon Technologies AG All Rights Reserved. Legal Disclaimer The information given in this document shall in no event be regarded as a guarantee of conditions or characteristics. With respect to any examples or hints given herein, any typical values stated herein and/or any information regarding the application of the device, Infineon Technologies hereby disclaims any and all warranties and liabilities of any kind, including without limitation, warranties of non-infringement of intellectual property rights of any third party. Information For further information on technology, delivery terms and conditions and prices, please contact the nearest Infineon Technologies Office (www.infineon.com). Warnings Due to technical requirements, components may contain dangerous substances. For information on the types in question, please contact the nearest Infineon Technologies Office. Infineon Technologies components may be used in life-support devices or systems only with the express written approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the failure of that life-support device or system or to affect the safety or effectiveness of that device or system. Life support devices or systems are intended to be implanted in the human body or to support and/or maintain and sustain and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may be endangered. BGB707L7ESD BGB707L7ESD as TV LNA Application Note AN232 Revision History: 2010-08-03 Previous Revision: Rev. x.x (previous) Page Subjects (major changes since last revision) Trademarks of Infineon Technologies AG A-GOLD™, BlueMoon™, COMNEON™, CONVERGATE™, COSIC™, C166™, CROSSAVE™, CanPAK™, CIPOS™, CoolMOS™, CoolSET™, CONVERPATH™, CORECONTROL™, DAVE™, DUALFALC™, DUSLIC™, EasyPIM™, EconoBRIDGE™, EconoDUAL™, EconoPACK™, EconoPIM™, E-GOLD™, EiceDRIVER™, EUPEC™, ELIC™, EPIC™, FALC™, FCOS™, FLEXISLIC™, GEMINAX™, GOLDMOS™, HITFET™, HybridPACK™, INCA™, ISAC™, ISOFACE™, IsoPACK™, IWORX™, M-GOLD™, MIPAQ™, ModSTACK™, MUSLIC™, my-d™, NovalithIC™, OCTALFALC™, OCTAT™, OmniTune™, OmniVia™, OptiMOS™, OPTIVERSE™, ORIGA™, PROFET™, PRO-SIL™, PrimePACK™, QUADFALC™, RASIC™, ReverSave™, SatRIC™, SCEPTRE™, SCOUT™, S-GOLD™, SensoNor™, SEROCCO™, SICOFI™, SIEGET™, SINDRION™, SLIC™, SMARTi™, SmartLEWIS™, SMINT™, SOCRATES™, TEMPFET™, thinQ!™, TrueNTRY™, TriCore™, TRENCHSTOP™, VINAX™, VINETIC™, VIONTIC™, WildPass™, X-GOLD™, XMM™, X-PMU™, XPOSYS™, XWAY™. Other Trademarks AMBA™, ARM™, MULTI-ICE™, PRIMECELL™, REALVIEW™, THUMB™ of ARM Limited, UK. AUTOSAR™ is licensed by AUTOSAR development partnership. Bluetooth™ of Bluetooth SIG Inc. CAT-iq™ of DECT Forum. COLOSSUS™, FirstGPS™ of Trimble Navigation Ltd. EMV™ of EMVCo, LLC (Visa Holdings Inc.). EPCOS™ of Epcos AG. FLEXGO™ of Microsoft Corporation. FlexRay™ is licensed by FlexRay Consortium. HYPERTERMINAL™ of Hilgraeve Incorporated. IEC™ of Commission Electrotechnique Internationale. IrDA™ of Infrared Data Association Corporation. ISO™ of INTERNATIONAL ORGANIZATION FOR STANDARDIZATION. MATLAB™ of MathWorks, Inc. MAXIM™ of Maxim Integrated Products, Inc. MICROTEC™, NUCLEUS™ of Mentor Graphics Corporation. Mifare™ of NXP. MIPI™ of MIPI Alliance, Inc. MIPS™ of MIPS Technologies, Inc., USA. muRata™ of MURATA MANUFACTURING CO. OmniVision™ of OmniVision Technologies, Inc. Openwave™ Openwave Systems Inc. RED HAT™ Red Hat, Inc. RFMD™ RF Micro Devices, Inc. SIRIUS™ of Sirius Sattelite Radio Inc. SOLARIS™ of Sun Microsystems, Inc. SPANSION™ of Spansion LLC Ltd. Symbian™ of Symbian Software Limited. TAIYO YUDEN™ of Taiyo Yuden Co. TEAKLITE™ of CEVA, Inc. TEKTRONIX™ of Tektronix Inc. TOKO™ of TOKO KABUSHIKI KAISHA TA. UNIX™ of X/Open Company Limited. VERILOG™, PALLADIUM™ of Cadence Design Systems, Inc. VLYNQ™ of Texas Instruments Incorporated. VXWORKS™, WIND RIVER™ of WIND RIVER SYSTEMS, INC. ZETEX™ of Diodes Zetex Limited. Last Trademarks Update 2009-10-19 Application Note AN232, Rev. 1.0 3 / 17 2010-08-03 BGB707L7ESD BGB707L7ESD as TV LNA List of Content, Figures and Tables Table of Content 1 Introduction ........................................................................................................................................ 5 2 Summary of Measurement Results .................................................................................................. 6 3 Schematic Diagram ............................................................................................................................ 7 4 Measured Graphs ............................................................................................................................... 8 5 Evaluation board and layout Information ...................................................................................... 11 6 Potential Performance Enhancements .......................................................................................... 12 Appendix 1: ESD protection circuit for system level ESD robustness .......................................................... 13 Author 16 List of Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Classical Three-Band Tuner ................................................................................................................ 5 Silicon Tuner ........................................................................................................................................ 5 Schematic Diagram .............................................................................................................................. 7 Gain ...................................................................................................................................................... 8 Noise Figure ......................................................................................................................................... 8 Matching ............................................................................................................................................... 9 Matching – Smith Chart ........................................................................................................................ 9 Isolation .............................................................................................................................................. 10 Picture of Evaluation Board with connector description ..................................................................... 11 PCB Layer Information ....................................................................................................................... 11 Gain vs. current consumption ............................................................................................................ 12 NF vs. current consumption ............................................................................................................... 12 ESD test pulse according to system level specification IEC61000-4-2 – Contact Discharge 15kV .. 13 Smart 2-step ESD protection approach based on external and internal ESD protection structure ... 14 Standard ESD protection topology with optional ESD resistor, blocking capacitor and a serial inductor ............................................................................................................................................... 15 List of Tables Table 1 Table 2 Table 3 Summary of Measurement Results ...................................................................................................... 6 Bill-of-Materials..................................................................................................................................... 7 1dB compression point and IP3 ......................................................................................................... 10 Application Note AN232, Rev. 1.0 4 / 17 2010-08-03 BGB707L7ESD BGB707L7ESD as TV LNA Introduction 1 Introduction Over the last few years there has been a clear trend in television to move from the classical TV-set out to more mobile platforms like notebooks, cell phones and PDAs. Especially the introduction of digital terrestrial television in many countries and the more and more evolving hand-held television standards like DVB-H and T-DMB support this evolution. With television going mobile the antennas are getting smaller, resulting in a loss in antenna gain. It requires an additional LNA with low noise figure to keep up a good reception of the TV signal, no matter if the TV tuner’s RF frontend uses the classical three-band tuner (Figure 1) or the more space saving silicon tuner (also called double conversion tuner or up-down converter, Figure 2). Particularly the silicon tuner has the need for and external LNA as tuner ICs in general tend to have high noise figures and the silicon tuner approach doesn’t implement any prestages including an RF MOSFET. The application for BGB707L7ESD shown in this document was designed for use in mobile TV applications having electrically short (telescope) antennas. The low current consumption of the LNA makes it ideal for mobile applications while still offering a good input compression point compared to this low current. The use of short antennas relaxes the requirements for linearity anyway. Being located directly after the antenna an LNA needs to be protected from ESD strikes. BGB707L7ESD’s builtin ESD protection of 2kV HBM at all pins (3kV at the RF input pin) helps a lot in meeting this requirement. In case of even higher protection levels being needed additional ESD protection using an Infineon TVS diode is highly recommended. For more details on ESD protection please refer to Appendix 1. VHF low 47 ... 160MHz LNA RF Input VHF high 160 ... 470MHz Tuner IC ESD Protection UHF 470 ... 860MHz RF MOSFETs Figure 1 Classical Three-Band Tuner SAW GSM Rejection LNA Demod ESD Protection VGA Mixer VCO 1 Si-Tuner Figure 2 Mixer VCO 2 Si_Tuner.vsd Silicon Tuner Application Note AN232, Rev. 1.0 5 / 17 2010-08-03 BGB707L7ESD BGB707L7ESD as TV LNA Summary of Measurement Results 2 Summary of Measurement Results All data was measured in a 50Ω system. Table 1 Summary of Measurement Results Vcc = Vctrl = 3.0V, at room temperature. Parameter Symbol Value Unit Frequency Range Freq 47-862 MHz DC Voltage Vcc 3.0 V DC Current Icc 2.9 mA Gain G 12.6 – 13.7 dB See Figure 4 Noise Figure NF 1.3 – 1.8 dB See Figure 5 RLin 4 dB See Figure 6 RLout 9 dB See Figure 6 IRev 24.5 dB See Figure 8 IP1dB -7.5 dBm See Table 3 IIP3 -11 dBm See Table 3 Input Return Loss Output Return Loss Reverse Isolation Input 1dB compression point rd Input 3 order intercept point Application Note AN232, Rev. 1.0 6 / 17 Note/Test Condition 2010-08-03 BGB707L7ESD BGB707L7ESD as TV LNA Schematic Diagram 3 Schematic Diagram Figure 3 Schematic Diagram Table 2 Symbol Bill-of-Materials Value Unit Size Manufacturer Comment C1 330 pF 0402 various DC blocking C2 47 nF 0402 various RF bypass C3 330 pF 0402 various DC blocking C4 47 nF 0402 various RF bypass C5 330 pF 0402 various DC blocking L1 470 nH 0603 Tayio Yuden LK1608 RF choke R1 12 kΩ 0402 various Current adjustment R2 1 kΩ 0402 various Feedback, matching R3 180 Ω 0402 various Stability, output matching Q1 BGB707L7ESD Application Note AN232, Rev. 1.0 TSLP-7-1 Infineon Technologies 7 / 17 2010-08-03 BGB707L7ESD BGB707L7ESD as TV LNA Measured Graphs 4 Measured Graphs All data displayed here was measured in a 50Ω system. Vcc = Vctrl = 3.0V Gain 15 DB(|S(2,1)|) 14.5 14 13.5 13 12.5 12 40 100 900 Frequency (MHz) Figure 4 Gain Noise Figure 2.2 2 NF (dB) 1.8 1.6 1.4 1.2 1 50 Figure 5 350 Frequency (MHz) 650 850 Noise Figure Application Note AN232, Rev. 1.0 8 / 17 2010-08-03 BGB707L7ESD BGB707L7ESD as TV LNA Measured Graphs Matching DB(|S(1,1)|) 0 DB(|S(2,2)|) -2 -4 -6 -8 -10 -12 40 100 900 Frequency (MHz) Matching Matching in Smith Chart 0.8 S(1,1) 1.0 Figure 6 2. 0 6 0. S(2,2) Swp Max 870MHz 0. 4 0 3. 0 4. 5.0 0.2 10.0 5.0 4.0 3.0 2.0 1.0 0.8 0.6 0.4 0 0.2 10.0 -10.0 2 -0. -4 .0 -5. 0 -3 .0 Figure 7 .0 -2 -1.0 -0.8 -0 .6 .4 -0 Swp Min 40MHz Matching – Smith Chart Application Note AN232, Rev. 1.0 9 / 17 2010-08-03 BGB707L7ESD BGB707L7ESD as TV LNA Measured Graphs Isolation -22 DB(|S(1,2)|) -22.5 -23 -23.5 -24 -24.5 -25 40 100 900 Frequency (MHz) Figure 8 Table 3 1 Isolation 1dB compression point and IP3 1 Frequency / MHz Input compression point / dBm Input IP3 / dBm 50 -7.5 -11 150 -8 -11 250 -7.5 -11 450 -7 -10.5 800 -6.5 -10.5 Test condition: -35dBm / tone, ∆f=1MHz Application Note AN232, Rev. 1.0 10 / 17 2010-08-03 BGB707L7ESD BGB707L7ESD as TV LNA Evaluation board and layout Information 5 Evaluation board and layout Information Cadj GND Vctrl Vcc RFin RFout boardandpins.vsd Figure 9 Picture of Evaluation Board with connector description Note: The pin “Cadj” may be used to adjust the IC’s current quickly by connecting an external resistor decade. Prior to doing this R1 has to be removed. If the board is intended to be used as received, please leave this pin open. Figure 10 PCB Layer Information Application Note AN232, Rev. 1.0 11 / 17 2010-08-03 BGB707L7ESD BGB707L7ESD as TV LNA Potential Performance Enhancements 6 Potential Performance Enhancements It is possible to increase gain and to reduce noise figure by increasing the current consumption of the IC. The data displayed here was acquired using a noise figure meter. This is the reason why the gain curves are not as smooth as they would have been when using a network analyzer. Figure 11 Gain vs. current consumption Figure 12 NF vs. current consumption Application Note AN232, Rev. 1.0 12 / 17 2010-08-03 BGB707L7ESD BGB707L7ESD as TV LNA Potential Performance Enhancements Appendix 1: ESD protection circuit for system level ESD robustness Introduction With the advancement in miniaturization of semiconductor structures, ESD handling capability of the devices is becoming a concern. Increasing ESD handling capability of the I/O ports costs additional chip size and affects the I/O capacitance significantly. This is very important for high frequency devices, especially when high linearity is required. Therefore, tailored and cost effective ESD protection devices can be used to build up an ESD protection circuit. To handle ESD events during assembly, devices normally have on-chip ESD protection according to the device level standards e.g. “Human Body Model” JEDEC 22-A-115. To fulfill the much more stringent system level ESD requirements according to IEC61000-4-2 as shown in Figure 13, the external ESD protection circuit has to handle the majority of the ESD strike. The best external ESD protection is achieved using a TVS diode assisted by additional passive components. m6 ESD_current, A 60 Reference Pulse 15kV contact discharge according IEC61000-4-2 m6 time=1.507nsec ESD_current=57.68 A m7 time=30.01nsec ESD_current=29.43 A 40 m7 m8 20 m8 time=60.01nsec ESD_current=15.18 A 0 0 20 40 60 80 100 120 140 160 180 200 time, nsec Figure 13 ESD test pulse according to system level specification IEC61000-4-2 – Contact Discharge 15kV Some examples of RF applications addressed by the Infineon ESD protection proposal are given below: • FM Radio (76 MHz -110 MHz) • WLAN 802.11b/g/n (2.4 GHz, Tx ~ +20 dBm) • Bluetooth (2.4 GHz, Tx ~ +20 dBm) • Automatic Meter Reading, AMR (900 MHz, TX ~ +20 dBm) • Remote Keyless Entry, RKE (315 MHz - 434 MHz - 868 MHz - 915 MHz, Tx~13 dBm) • GPS (1575 MHz, Rx only but can be affected by RF interferer) For an ESD protection device tailored for medium power RF signals (=< +20 dBm), following requirements are essential: 1. RF requirements a) Bidirectional characteristic to handle DC free signals without clipping / signal distortion b) A highly symmetrical behavior of the ESD device for positive and negative voltage swings is mandatory to keep the power level of even Harmonics low c) Breakdown voltage of 5 V-10V, to avoid signal distortion at high RF voltage swing applied at the TVS diode, located close to the antenna d) High linearity e) Low leakage current and stable diode capacitance vs. RF voltage swing f) Ultra low diode capacitance is mandatory Application Note AN232, Rev. 1.0 13 / 17 2010-08-03 BGB707L7ESD BGB707L7ESD as TV LNA Potential Performance Enhancements 2. ESD requirements a) Lowest dynamic resistance Rdyn to offer best protection for the RFIC; Rdyn is characterized by Transmission Line Pulse (TLP) measurement b) Very fast switch-on time (<<1nsec) to ground the initial peak of an ESD strike according to IEC61000-4-2 c) No performance degradation over a large number of ESD zaps (>1000) Two-step ESD Protection approach General structure for a 2-step ESD approach according to Figure 14 enables to split the entire ESD current between the internal and external ESD protection device. The external device is much more robust and handles the majority of the ESD current. To avoid any impact on the RF behavior of the system and to minimize non linearity effects, the TVS diode should possess an ultra low device capacitance. Therefore the bi-directional (symmetrical) Infineon TVS Diode ESD0P2RF is well suited, which provides a diode capacitance as low as 0.2 pF and a Rdyn of only 1 Ohm. ESD robustness can be improved one step more by adding a small serial resistor between the external TVS diode and the RF amplifier input. A resistor of ~2.2 Ohm is a good compromise between additional ESD performance and insertion loss. The TVS diode ESD0P2RF in combination with the 2.2 Ohm ESD resistor would incur less than 0.23dB insertion loss up to 3 GHz. Figure 14 Smart 2-step ESD protection approach based on external and internal ESD protection structure For further ESD improvement it is highly recommend to add a serial capacitor (C1). The capacitor cuts off most of the high energy created by the ESD strike. For better ESD robustness, C1 should be as small as possible, but has to match to the intended application frequency as well. For a broadband ESD protection (80MHz…3GHz) C1 should be about 100pF…150pF. Optional matching can be implemented with a serial inductor L1 for a dedicated frequency. In combination with L1, C1 can be reduced significantly which improves the ESD performance. Application Note AN232, Rev. 1.0 14 / 17 2010-08-03 BGB707L7ESD BGB707L7ESD as TV LNA Potential Performance Enhancements Figure 15 Standard ESD protection topology with optional ESD resistor, blocking capacitor and a serial inductor Application Note AN232, Rev. 1.0 15 / 17 2010-08-03 BGB707L7ESD BGB707L7ESD as TV LNA Author Author Dietmar Stolz, Staff Engineer of Business Unit “RF and Protection Devices” Application Note AN232, Rev. 1.0 16 / 17 2010-08-03 w w w . i n f i n e o n . c o m Published by Infineon Technologies AG AN232